If you use your mind to study reality, you won't understand either your mind or reality. If you study reality without using your mind, you'll understand both. . . . The mind and the world are opposites, and vision arises where they meet. When your mind doesn't stir inside, the world doesn't arise outside. When the world and the mind are both transparent, this is true vision. And such understanding is true understanding.
BodhidharmaAll Buddhas preach emptiness. Why? Because they wish to crush the concrete ideas of the students. If a student even clings to an idea of emptiness, he betrays all Buddhas.
Bodhidharma